The Cell Nucleus, Volume III: Nuclear Particles, Part A covers topics on "splicing" and "processing" and on the controls of transcriptional and transport events that must be essential to cells that are either growing and/or are phenotypically differentiated. The book discusses the immunolocalization and structural organization of nascent RNP; the in situ localization of RNA structures; and the morphogenesis, cytochemistry, and putative role of perichromatin granules. The text describes transcription in the isolated nuclei; the isolation and structure of the ribonucleoprotein fibrils containing heterogeneous nuclear RNA; and low-molecular-weight nuclear ribonucleoprotein particles. The sequence, function, and role of U snRNAs of nuclear snRNPs; the maturation of low-molecular-weight RNA species; and the properties of the heterogeneous nuclear RNA-protein complexes and nuclear matrix are also encompassed. The book further tackles human antibodies to RNA-containing particles. Cellular biologists, microbiologists, pharmacologists, geneticists, and students taking related courses will find the book useful.